Feeding mechanism for sewing machines



June 24, 1930. J, BERGER 4 1,768,104

FEEDING MECHANISM FOR SEWING MACHINES Filed May 10, 1928 2 Sheets-Sheet i June24, 1930. E R 1,768,104

FEEDING MECHANISM FOR SEWING MACHINES Filed May 10, 1928 2 SheetsSheet 2 Patented June 24, 1939 UNITED STATES PATENT OFFICE JOSEPH BERGER. F UTICA, NEW YORK, AssIeNoR o UNION sPEcIAL MACHINE COMPANY, OF enrcneo, rumors, A coRreRArroN 0 ILLINOIS FEEDING MECHANISM FOR SEWING MACHINES Application filed May 10, 1928. Serial No. 276,783;

The invention relates to new and useful improvements in feeding mechanisms for sewing machines, and more particularly to a feeding mechanism for a sewing machine having a cylindrical work supporting arm for feeding the material lengthwise-of the arm as it is stitched. I

An object of the invention is to provide a feeding mechanism wherein the feed dog is moved back and forth by a direct thrust on the feed bar centrally thereof. I

, A further object of the invention is to provide a feeding mechanism for sewing ma chines of the above type wherein the actuating parts are so positioned relative to each other as to reduce the lateral dimensions of the feeding mechanism to a minimum so that the arm of the machine may be relatively small. These and other objects will in part be obvious and will in part be hereinafter more fully disclosed. v

- In the drawings which show by way of illustration one embodiment oflthe invenion V Q 7 v Figure 1 is a view partly in front elevation and partly in vertical section of a machine embodying the improvements.

Fig. 2 is a sectional view through the work supporting arm showing the feeding mechanism therein in plan, the looper and spreader mechanism being omitted'..

s Fig. 3 is a sectional view on theline 3-8 of Fig. 2. I

The feeding mechanism embodyingthe invention is particularly adapted for a sewing machine having a work supporting arm along which the material is fed while it is being stitched. The material is preferably fed off the end of the arm. In order to accomplish this the feeding mechanism in cludesja feed dog which has four ,motions and during its feeding motion it movesin a directionlengthwise of the arm'and toward the. free end of the arm. The feed dog is carried by a feed bar whichextends longitudinally of the arm to c a point adjacent the depending member on which the arm is suspended. The feed dog is raised and lowered by means of a lever connected by links to the feed bar adjacent the forward end thereof. 7 i I This lever is oscillated by an eccentric strap cooperating with an eccentric on the main shaft which in the present type ofmachine is disposed in the upperframe of the machine. The feed bar is moved back and forth by a rocking-frame which is oscillated by a rock shaft, and therock shaft, in turn, is oscillated by an eccentric strap cooperating with an eccentric on the main shaft. The novel features of the invention are particularly found in the construction of the feed bar and the arrangement of the rocking frame and the connection thereof to the feed bar. The feed bar has a raised bridging portion adjacent its rear end and the rocking frame is provided with an adjustable. stud extending underneath this bridging portion.

This stud is mounted 1n a slot so that it can be shifted for varying the stroke imparted to the feed bar. A link connects the stud to a forked'portionin the feed bar well beyond the longitudinal center of the. feed bar. The link is so disposed as to .--1ie sub stantially in a vertical plane containing the longitudinal center axis of thefeed bar.

Referring more in detailto the drawings: The invention is shown as applied to a sewing machine having a supporting. base 1 on which is mounted an overhanging brack; et ,2 carrying a frame 3 at its upper outer end.; Mounted in said frame is a main shaft 4. At one end ofthis frame is a: forwardly ating with the needles beneath the work sup port are 'loopers 9, 9, one for each" needle, and cooperating spreader 10. l I

The mechanism for operating the loopers and the mechanism for. operating; the spreader form no part of the pr'esent'invention, but are showndescribed and cla med with theloopers is a loop in my copending application, Serial Number 275,068, filed May 4, 1929.

plane substantially centrally of the work supporting arm. Said feed bar is mounted adjacent the feed dog on supporting links 18. which in turn are mounted on a lever 14 pivoted at 15. The lever 14 is oscillated by means of an eccentric strap 16 which cooperateswith an eccentric 17 on the main shaft 4. The main shaft 4 extends lengthwise of the upper frame and actuates devices at one end thereof for reciprocating the needle'bar, and also actuates devlces at i 1 they other end thereof for operating the looper and spreader.

The feed bar at the rear end thereof is forked as indicated at 19. This forked end of the feed bar straddles a pin 20. The pin 20 is journalled in a rocking frame 21. This rocking frame is mounted for oseilla tion on a supporting rod 22. This rocking frame is provided with a segmental slot 23 in which is mounted a stud 24. The stud is capable of being adjusted in the slot and secured in adjusted positions. A link 25 engages the stud 24 at one end and the other end of this link extends between the forks 26, 27 formed inthe feed bar. A pivot pin 28 secures the link to this portion of the feed bar. When the rocking frame is oscillated back and forth the link will impart an endwise thrust for moving the feed dog for.

feeding the material and this endwise thrust on thefeed bar is applied to the feedbar substantially at the center line. of the feed.

bar. This avoids lateral strain and cramping of the feed bar as it moves back and forth.

The feed bar is guided in its back and forth movements by hearing blocks 29, 29 carried bythe arm. This direct thrust reduces to a minimum the wear on the guide blocks and insures that the feed dogwill move uniformly in the same path during the stitching of the fabrics.

The-rocking frame 21 oscillated by I means of a'link 30 which is connected to a stud carried-by the rocking frame at one end and to afstud carried by an arm. 31

mounted onla sleeve '32,- which, in turn, is

mounted for free] oscillation on a shaft 33. ,The 'fsleeve carries a second arm 34 pro fvid'ed with aballstud 35 with'whi'ch an eccentric strap 36 cooperates. This eccentric strap engages an eccentric 37 on the main shaft 4.

*From the aboveit will be: apparent that have provided a feeding mechanism where n the parts for'moving the feed bar -back and'forth and i'aislng-and lowering tially in line with the feed bar, being disposed substantially centrally of. theline of feed, and this contributes to a feeding mechanism wherein the machinemay be operated at a very high speed with very little vibration of the parts.

' It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1'. A feeding mechanism for sewing machines comprising' a fed bar, a feed dog carried at one end thereby, means for slidingly supporting the otherend of the feed bar, means for'raising and lowering the end of the feed bar carrying the feed dog, and means for movingsaid feed bar endwise including alink pivoted to the feed bar intermediate itsends and lying in a vertical plane substantially coincident with the line ing frame for sli dingly supporting the other end of said feed bar, means for raising and lowerlng the end of the feed bar carrying the feed dog and means for moving said feed bar endwise including a link connected at one end 'to said swin ing frame at a point. substantially beneath t e feed bar and con-' nected at its other end to said feed bar, said link lying substantially in a vertical plane coincident with the line'of feed.

chines comprising a feed'bar, a feed dog carried at one end of said feed bar, a

swinging frame at the other end of said feed bar supporting a fulcrum pin, said feed bar having its end forked and-slidingly engaging said fulcrum pin; means connected to 3. A feeding mechanism for sewing ma the feed bar for raising andlowering the.

end thereofcarrying the feed dog, a link shiftably connected at one end to said swinga ing'frame substantially beneath the feed bar and'connected at the other end to the fe'ed bar, said linklying substantially in avertical plane coincident with the line of feed.

4. A feeding mechanism for sewing ma- .,chines comprising a feed 'barfa :feed dog carried at one end of said feed bar, a swing ing frame at the other endof said feed bar supporting a fulcrumpin, said feed bar I having its end'forke d and slidingly engaging said fulcrum pin, means connected to the feed bar for raising and lowering the end thereof carrying the feed dog, a link shiftably connected at one end to said swinging frame substantially beneath the feed bar and connected at the other end to the feed bar, said link lying substantially in a vertical plane coincident with the line of feed, said feed bar having a forked portion between which the ends of the link extend and a pin passing through the forked portion and through the link.

5. A feeding mechanism for sewing machines comprising a feed bar, a feed dog carried at one end of said feed bar, a swinging frame at the other end of said feed bar supporting a fulcrum pin, said feed bar having its end forked andslidingly engaging said fulcrum pin, means connected to the feed bar for raising and lowering the end thereof carrying the feed dog, a link shiftably connected at one end to said swinging frame substantially beneath the feed bar and connected atthe other end to the feed bar, said link lying substantially in a vertical plane coincident with the line of feed, said feed bar having an upwardly curved bridging portion extending over the link connection with the swinging frame.

6. A feeding mechanism for sewing machines comprising a feed bar, a feed dog carried at one end of said feed bar, a swinging frame at the other end of said feed bar supporting a fulcrum pin, said feed bar having its end forked and slidingly engaging said fulcrum pin, means connected to the feed bar for raising and lowering the end thereof carrying the feed dog, a link shiftably connected at one end to said swinging frame substantially beneath the feed bar and connected at the other end to the feed bar, said link lying substantially in a vertical plane coincident with the line of feed, said feed bar having a forked portion between which the ends of the link extend and a pin passing through the forked portion and through the link, said feed bar having an upwardly curved bridging portion extending over the link connection with the swinging frame,

7. In a sewing machine the combination of a cylindrical work supporting arm, a

feed bar extending lengthwise thereof, and carrying a feed dog at its outer free end,

means connected to the feed bar for raising and lowering the end carrying the feed dog, a swinging frame mounted in said work supporting arm with which the inner end of the feed bar has a sliding fulcrum engagement, a link located beneath the feed bar and connected at one end to said swingstantially in a vertical plane coincident with the line of feed.

8. In a sewing machine the combination of a cylindrical work supporting arm, a

feed bar extending lengthwise thereof, and

carrying a feed dog at its outer free end,

means connected to the feed bar for rais-- over the connection between'the link and the swinging frame.

9. In a sewing machine the combination of a cylindrical work supporting arm, a feed bar extending lengthwise thereof, and carrying a feed dog at its outer free end, means connected to the feed bar for raising and lowering the end carrying the feed dog, a swinging frame mounted in said work supporting arm with which the inner end of the feed bar has a sliding fulcrum engagement, a link located beneath the feed bar and connected at one end to said swinging frame, said link being connected at its 9 other end to the feed bar and lying substantially in a vertical plane coincident with the line of feed, said feed bar having an upwardly curved bridging portion extending over the connection between the link and the swinging frame, said feed bar having a forked portion to receive the end of the link and a pin passing through the forked portion for joining the link to the feed bar.

In testimony whereof, I affix my signature.

JOSEPH BERGER. 

